Electric synchronous motor



April 12,` 1938. H. JUNGHANS 2,113,693

ELECTRIC SYNCHRONOUS MOTOR Filed Feb. 1s, 193s Affe/wey Patented Apr'. 12, 1938 UNITED ASTATES PATENT OFFICE Eckenhof,

Application February 18, 19396, Serial No. 64,577 In Germany October 18, 1935 4 claim. (ci. 17e- 215) It is required of synchronous motors, such as are preferably used for driving the movement mechanisms of clocks, for driving talking machines and for similar purposes. that it should be 5 possible for them to bedriven with diii'erent potentials. For this purpose, two windings and,- consequently, three connecting terminals are generally provided, for example for potentials of 110 and 220 volts. These precautions increase the cost of production, necessitate materials (copper) whichl cannot be produced in suiiicient quantitles in the country and require of inexperienced persons who wish, for example, to change over the synchronous clock to another potential, a certain amount oi' skill and consideration, that is to say, they aii'ord a. source oi danger if not carefully handled. The object of the present invention is to simplify synchronous motors for several potentials,

such as are installed, in particular, in household instruments, both with regard to their manipulation by unskilled persons and with regard to their construction. According to the lnvention, this object is achieved owing to the fact thatwhile use is made o! a single coil winding the adaptation to the supply voltage at a given moment is eected by corresponding iniiuencing of the magnetic aux. According to a further feature `of the invention, it is consequently posible, with in- 80 creasing potentials, to insert corresponding shunt membersinthe magnetic circuit for keeping constantthe magnetic iiuxacting attherotor. Itis preterabletouseasshuntmembersiron whichcanbesecuredtothestatcrw'iththeirends .nex'ttobothendsotthecdl. Accordingtoamrther feature of the invention, the shunt members areeconstruetedasstirrup adaptedtobeiittted orciampedontoandireelyremovedfromthe stator or intermediate members which may, if 4,0 reqmreabepmvideaumn. nmnyuiemuns membersmaybepermanentlyconnectedwilhthe ststoniorexamplebyarticuiationtocneside, ,sotlnttheymerelyneedtobcpivotedioreonnection or disconnection. Y u Twoconstructionalexamplesoi'theinvention armilhtratedintheaccomlilnying drawinin w e llguresiand2aresideandfmntelevations 5o mvelyctasynchronousmotoriorsnclectrieelcehwithashuntstirrupadaptedtobe l'igmes3and4ahomalsoinsideandn'cnt eievatiomasynahronmmotorwlthashunt Ilm-mtobeclampedon.

.Letters Patent is:`

Figs. 5 and 6 are plan and front views respectively of a modined construction.

'Ihe synchronous motor illustrated in Figures 1 and 2, which is intendedto drive the movement mechanism of a so called synchronous clock, has g a singlewinding 2 with two terminals 4 for the current leads. On both sides of the ends oi' the coil 2, the horseshoe-shaped stator i is traversed by screw bolts la. By means oi' the said screw bolts and nuts 3, the shunt stirrup l bridging the 1o coilintheformofawideironrail I maybes'ecured. Slots Ila are provided in the stirrup I in order that it may be secured in a simple manner, so that after simple loosening Aof the nuts l the stirrup may be withdrawn or pushed in from the 15 side.

The manipulation of the stirrup is further simxiiied if it can be clampedon the stator. for example, by its natural resiliency. Buch an arrangementisshowninFigures3and4. Thego screwboltsiaandthenutsserveinthiscase, for the permanent securing of intermediate members or stirrup holders Ila with inclined engagement surfaces IIb, with which engage the ends, also inclined, ot the resilient shunt stirrup i.. 25 '111e manipulation oi' the shunt members takes place without any loosening or operation oi securing means, such as screws or nuts. merely by pressing on and lifting.

The illustrated methods of securing the shunt stirrupsaremerelyexampiesofalargenumber ci' simple and convenient lreans of fastening, which are seit-evident from the foregoing references.

l'ls.5and6iliustratethemodiiicationin35' whichthestirrup l withitsoneendissecuredto neend oithestatorbymeansotthescrewand boit lwhiletheotherendisprovided withaslot llinthestirrup Lwhichwhenthestirmpis turnedintotheworkingposition-asshovwnit40 slidesoverapin Nattheotherendotthestator andaspring l1 hoidsthestirrupresilientlyin Winatlclairnasnewancidesiretosecureliy ilnasynchronous electro-motoradaptedto bedrivenhwdiiierentvoltageaasingle-coilwindim,arotor,astator.and ashuntstirrupior eschotthehisiiervoltagesforkeepimconstsnto themagneticmixactingatthesaidrotorund anlncreasedvoltage. e

2.Amotoriorusewithdiilerent mnnlrvoltaseaeomnrhingasinsleconwinmng withthesametelmimlsforccnnectionto'the supply for high and low voltages, a rotor, a stator, a removable magnetic shunt, and means for securing said shunt to the `stator with its ends adjacent the vends of the coil, said shunt being capable of maintaining substantially the same magnetic ux in the rotor at a high supply voltage as prevails therein at a low supply voltage with the shunt removed.

-3. A synchronous motor for use with different supply voltages, comprising a single coil winding with the same terminals for connection to the supply for high and low voltages, a rotor, a stator, and a removable magnetic shunt capable of maintaining substantially the same magnetic ilux in the rotor at a high supply voltage which prevails therein at a low supply voltage with the shunt rup oi iron pivoted at one end to the stator and with its other end movable resiliently into engagement with the stator to render the shunt operative.

HELMUT JUNGHANS. 

